Facebook is holding a launch event this evening but what the social network
plans to announce remains secret. Shane Richmond considers some of the
possibilties.

Since Facebook sent out invites to an event at its California headquarters this evening there have been several rumours about what the company plans to announce. They range from speculation about a major move into hardware, perhaps by launching a Facebook phone, to more mundane rumours about a minor new service, such as an iPad app for Facebook messages.

The company has been tight-lipped. The technology industry is gradually embracing the Apple approach to launching a new product - develop in secret, build anticipation by holding a launch event and then make the big reveal in the glare of the world's media. For maximum impact, the new product should be available as soon as possible after the launch event.

This is a significant change. Technology companies often used to discuss forthcoming products, show off prototypes and drip-feed news of their progress. As a result, by the time of the launch, the product would often receive little fanfare.

Apple is now watched so closely that details of its new products regularly leak in advance. In contrast, Facebook has successfully maintained secrecy around tonight's announcement. So what could it be?

A Facebook phone The biggest thing Facebook could announce tonight is also the least likely. For one thing, if Facebook had built its own handset then news would probably have leaked from the supply chain or from mobile carriers. It's possible that Facebook is going to announce plans to move into hardware, but a finished product seems unlikely.

A new search engine It's been known for some time that Facebook wants to do something search related. Mark Zuckerberg, Facebook's chief executive, said last September: "Facebook is pretty uniquely positioned to answer the questions people have. At some point we’ll do it. We have a team working on it."

Earlier today, gadget blog Pocket Lint reported that the social network is about to unveil a search feature. How it would work is unclear but Zuckerberg's quotes from last year suggest a question-and-answer service, similar to Quora, rather than a Google-style engine for searching the web. This is the best guess for what Facebook has planned.

An iPad messaging app It was reported yesterday that Facebook is planning a dedicated iPad app for messaging. The existing Facebook application supports messaging but this would be a stand-alone service, more like an instant messenger app. If that's true and it's being announced this evening, it will either be an aside to a bigger announcement or a massive anti-climax.

A redesign for Timeline and/or the news feed Facebook overhauls its design regularly to better reflect how people are using the service or to showcase new features. It's been rumoured that this time round Facebook is planning to unveil a new design for the newsfeed on mobile devices. TechCrunch reported yesterday that this feature was being tested but had "no information on when this could be released".

Paid-for messaging Facebook has been testing charges for messaging users who are outside your circle of friends. It costs, for example, $100 to message Mark Zuckerberg. The social network says it wants "to determine whether adding a 'financial signal' improves its formula for delivering 'relevant and useful' messages to members' inboxes". Assuming this does become a fully-fledged service, rather than a test, it seems too niche to be the centrepiece of an announcement.